Spray gun having disk, diaphragm and plug construction



June 1965 P. F. GEORGE ETAL 3,186,643

SPRAY GUN HAVING DISK, DIAPHRAGM AND PLUG CONSTRUCTION Filed March 4, 1963 (g2 INVENTO S BY [504/430 M Co mo Jrraewifis United States Patent 3,186,643 SPRAY GUN HAVING DISK, DIAPHRAGM AND PLUG CQNSTRUCTION Philip F. George, San Diego, and Leonard M. Collins, Los Angeles, Calif.; said Collins assignor to Mario J. Manetti and Fred P. Manetti, both of Chicago, Ill. Filed Mar. 4, 1963, Ser. No. 262,757 6 Claims. (Cl. 239-318) reservoir for the chemical to be mixed with water and sprayed. Water proceeds through a main passage or bore of the gun from a hose nozzle to which it is attached. The main passage has a throat or section of reduced diameter leading abruptly into a larger bore or expansion chamber. A zone of reduced pressure is produced in the expansion chamber because of the Venturi effect. As soon as the pressure is so reduced in the expansion section, the suction created draws a chemical solution in the container through a secondary passage into the stream of water.

i The reservoir for the chemical communicates with the secondary passage by means of tubing. The reservoir is held at atmospheric pressure and the chemical solution in the reservoir therefore travels into the main passage, via the tubing andsecondarypassage, due to the I reduced pressure in the expansion chamber. The chemical solution is thus intermixed with water and then flows to the outlet end of the gun.

In spray guns of the type described, there is a tendency for the chemical solution to be sucked back into the hose itself when the water is shut 01f at the main source. In order to prevent this, anti-siphon valves, or backfiow preventing devices have been employed in the prior art.

Our invention has as its major object the improvement of such anti-siphon devices in terms of increased sealing immediately after water shut-01f, While still permitting instant operability of the device in response to water pressure.

Another major object of the present invention is to pro- 3,186,643 Patented June 1 1965 "ice FIGURE 2 is a side elevational cross-section of our hose spray gun shown with the anti-siphon valve in open position;

FIGURE 2a is an exploded perspective view of the antisiphon valve utilized in our hose spray gun;

FIGURE 2b is an elevational view of the downstream side of the flexible or resilient diaphragm of our antisiphon valve;

FIGURE 3 is a side elevational cross-section of our hose spray gun shown with the anti-siphon device in normally closed position;

FIGURE 3a is an enlarged fragmentary view of the anti-siphon device as shown in FIGURE 3;

1 FIGURE 4 is a fragmentary cross-sectional view, in plan, taken along the line 44 of FIGURE 3;

FIGURE 5 is a fragmentary cross-sectional view, in plan, taken along the line 44 of FIGURE 3, but showing a proportionating valve in the spray gun rotated 90 from its position in FIGURE 4;

FIGURE 6 is an elevational cross-sectional view taken along the line 6-6 of FIGURE 2; and

FIGURE 7 is a partially cut-away plan view of our spray gun.

In general, our invention comprises a spray gun adapted to be mounted onto a suitable container. Water enters the main bore of the gun from a water hose, and an antisiphon device is located at the inlet end. The anti-siphon device is instantly openable in response to water pressure, and provides a positively leakproof mode of operation. This is accomplished by a combination of a flexible or resilient diaphragm, a rigid perforate disk, and a plurality of sealing members incorporated into the diaphragm.

A proportionating valve is located intermediate the inlet and outlet ends of the gun. The valve is provided with a port in constant communication with the container carrying the chemical solution. .T he effective diameter of the main passage can be varied so that the ratio of chemical solution to water can also be varied. In general terms therefore, we have provided an improved spray gun in several respects.

Referring now to the drawings, the spray gun of our invention is designated by the numeral 10. The spray gun 10 is adapted to be mounted onto a container 12 by means of screw cap 14, preferably integrally formed with the gun 10. A water hose 16 is adapted to be attached to the gun by means of hose cap 18, preferably integrally I formed with the gun 10.

vide a single cap controlling a plurality of functions, i.e.,

and which is leakproof during operation, while also having a plurality of sealing members which prevent back flow of chemical solution upon water shut-off.

These and other objects of the present invention will I become clearly understood by referring to the following detailed description and accompanying drawings wherein: FIGURE 1 is a perspective view of our hose spray gun mounted onto a reservoir containing a chemical solution;

The spray gun proper is preferably made of molded plastic and comprises a generally tubular body 20, the axis of which is generally perpendicular to the axis of the container 12. The body 20-has a main bore 22 passing centrally therethough. A secondary bore 24 passes perpendicularly through the main bore 20 intermediate the inlet and outlet ends of the spray gun 10.

The body or stem 32 of a proportionating valve or plug 26 passes through the secondary bore 24, the plug 26 invide a spray gun wherein an anti-siphon valve isprovided which is instantly openable in response to water pressure,

eluding an enlarged head or handle 28 formed integrally with the stem 32. v I

The stem 32 fits tightly within the secondary bore 24 to prevent leakage, but is rotatable therewithin. The stem 32 is provided with a T-shaped passage, the normally horizontal portion of the 'I (as shown in FIGURES 2 and 3) comprising a bore 34 of varying diameter 34a, 34b. The normally vertical portion of the T has a central passage or port 36 passing from the bottom edge 38 of the T- shaped passage and into the bore 34a preferably, immediately adjacent the point at which the diameter of bore 34 abruptly narrows.

.The stem 32 of plug 26 is provided with attachment neans, for tubing40, integral with the bottom of stem 32, the attachment means taking the form of a sleeve 42 within which the tubing 40 can be tightly fit.

'aunitr.

ring or head 58. 1

3 Chemical solution in the container 12 is thus always in communication with the bore 34 of plug 26 by means of tubing 40 and passage 36. v The head or handle-26 is rotated within secondary bore 24 until plug bore 34b is coaxial with the main bore 22, thereby fixing the ratio of chemical solution to water.

FIGURE 4 shows clearly the just-described position of bores 34a, 34b, with bore 341) being positioned adjacent the water inlet end of the gun 10. In this position, water entering main bore 22, under pressure fromthe Water hose 16, rushes into small bore 34b, and expands in enlarged bore 34a creating suction which causes the chemical solution to be drawn into the passage 36 via tubing 40, and thence into bore 34!). The chemical is thereby. admixed with waterin bore 34a in predetermined proportion. The admixture of water and chemical solution thence-passes to the outlet end 44 of the gun 10.

When larger bore 34a is located adjacent the Water inlet side of the gun 10, only water will pass through the gun since chemical will not be sucked in through passage 36 because no expansion chamber is now'provided.

A deflector plate 46 is rotatably mounted, within enlarged bore 22b of the outlet end '44, by means of a cylindrical extension or sleeve 48 integrally formedwith the deflection plate. The water thus rushing into outlet end 44 may thereafter be deflected to any desired. area by means of'deflector plate 46.

The .water may be shut off'at the spray gun itself, rather than at the water inlet to the hose, by turning head 28 of plug 26 so that bores 34a, 34b, are out of com munication with main bore 22, as shown in FIGURE 5.

It will be understood that the ratio of chemical solution to water can be varied to a great degree by merely pro-. viding bores 34a, 34b of different diameters for a stem 32 of an additional plug 26.

As is normal in the art, thecontainer: 12 is maintained at atmospheric pressure by means of an openingleading from the interior of the container 12 to the atmosphere. This opening is provided by means of a passage or vent 90 leading through the body 20; The vent 90 passes through to the upper side of the body 20 terminating in a sealing ring 91 (see FIGURES 2, 3 and 7).-

4 FIGURES 4, 3 and 3a, when water-is not'flowing through the hose 16.-

Surrounding the central area 60 is an imperforate annular portion 64 having an upraised sealing ring 72, and an outer thickened imperforate section 70. The sealing ring 72 and imperforate'section 70 sealingly contact the disk 52 when Water is not flowing through hose 16, as shown in FIGURE 3a especially.

An ordinary washer 63may be inserted at the point of connection of the Water hose lto the spray gun screw cap 18 to. insure against leaks, or a thickened bead 58 may be provided to act both asa washer and as a retainer 7 for the disk '52.

shown in FIGURES 5 and 7), the vent 90 is sealed off by means of. a cylindrical projection or boss 92 integrally formed on the cross-ribbing 94 of the head 28 of the valve26.. In this off position, no chemical or water can flow, and since the vent is shut 01f, no spillage can occur, even if the container and valve are shipped or handled as When the valve 26 isturned to the positionof FIGURE 2, the vent 90 is opened tothe atmosphere since air communicates with the vent through small openings 96 formed in the head 28. V

An anti-siphon device is located at the inlet end of the gunltl and comprises essentially two elements. The

first element is a perforated, flat, round, substantially spaced :from the center of the disk 52. The fiat disk 52 thus' has an unperforated central section 53, a perforated annularsection spaced from the centerof the an unperforated outer portion 55; e i

The second element of the anti-siphon device 50 comprises a resilient or flexible circular diaphragm member 56. Thediaphragm 56 is preferably made of rubber, and I has a raised peripheral retaining ring or bead 58 (see. FIGURES 2, 2b-and 3). The disk 52 is held in intimate contact with the diaphragm 56 by means of the retaining The central portion or area 60'of diaphra'gm 56 is m.

.vided with apair of slits, made by a pair of intersecting cuts 62 (see FIGURES 2 and 2b, especially). 'The central Turning now to the operation of the anti-siphon device or valve 50, aswater enters the spray gun 10, it must first pass through the perforations 54 of disk 52.

The force of the water .thendistends the central-area 60 of the rubber diaphragm 56, as shown in FIGURE 2, and allows Water. to fiow through the opening 61,thus formed in the valve 50 (see FIGURE 6). The Water travels into main bore 22, where it is admixed with chemical solution entering bore 22, via passage 36, as heretofore described.

To facilitate the distention of central area 60, the annularvportion 64, as well as the central area 60, is thin- Walled with-respect. to the outer portion70. Thus, for example, the outer portion'may be of 0.030 inch thickness, while the portion 64 and central. area 60 are 0.020 inch in thickness. The thin-walled portions of the diaphragnrfidnamely in central area Gti'and in annular area 64,,great1y facilitate instant vopening of the central area 60in response to water pressure. 7

As the diaphragm 55 distends in response to Water pressure, the downstream side thereof abuts. generally cylindrical extension 66, as clearlyseen in FIGURE 2. Thus, as water flows into the main bore 22, Water leakage is positively prevented by the seal'provided between the diaphragm 56 and the cylinder 66.

Upon shut-off of the water pressure'the diaphragm 56 immediately assumes the position shown in FIGURES 3 and 3a, in which the diaphragm 56 and the disk 52 are in intimate contact. In order topositively prevent backflow upon water shut-off at the water source, the central and outer portions 69 and '70 ofdiaphragm 56, together with sealing ring 72, all abut the downstream side of the disk 56, and thus act as sealing members. Sealing ring 72 and surfaces 60 and 70all'1ie in one plane and intimately contact the downstreamside of'disk-SZ. The. presence ofa plurality of sealing members is important since his possible for the'central surface area 60- to be come clogged by a particle, and not exert any sealing action. However,. the-other sealing members can still exertjtheir nonnalsealing function, and thus .prevent any backfiow of chemicalsolution into the water line.

Additionally, the cuts orslits 62; are made on the bias,

. that is, the. cuts are angularly disposed with respectto the disk, and

axis of thedisk 52 itself, as clearly shown in FIGURE 2,

1 Thus, whenthe centralj area 60 returns to'its normal seal ing position (FIGURES 3'and-3a), the bias cuts 62 provide greater sealing surface than would cuts made. parallel to the axis of. disk 52. -Afmaximum sealing effect is thus 7 obtained;

It will thus be seen that an anti siphfon valve 50 is provided in ourspray gun which is instantly'openablein response to water pressure, :is positively leakproof while a in the open positio'mand on returning'to closedposi-j tion, presents a plurality of sealing. members for the taneously withclosure ofthe vent andeasily chithged'by...

' the simple; turn of a dial;

area/6t} is held in intimate contact with the central, un-' i perforated area 53 of the disk 52, asQis ibestj seeu in;

a While one. preferred,.embodimentof' the. present raven:

tionhasbeen' shown "anddes' 'cribed, manyfchanges and modifications can be madeitherein without departing from the principles of our invention. Therefore, we intend to be bound only by the scope of the claims which follow.

We claim:

1. In a device for preventing backflow of fluid, the combination which comprises:

a conduit for fluid having an inlet portion and an outlet portion;

a substantially rigid flatdisk disposed across the conduit in the inlet portion and having a generally annular perforate portion surrounding a central imperforate portion; and

a generally flat resilient diaphragm disposed across said conduit on the outlet side of and adjacent said disk, said diaphragm having a normally flat central slit portion aligned with said central imperforate portion of said disk, a relatively thick outer imperforate portion for covering said annular perforate portion of said disk, and a relatively thin intermediate annular imperforate portion disposed between said central and outer portions, said intermediate annular imperforate portion having an annular bead formed thereon, said flat central slit portion, said intermediate annular bead and said outer imperforate portion of said diaphragm contacting said disk when said diaphragm is in undistended position to provide a plurality of sealing members preventing back flow of fluid from said outlet to said inlet through said slit portion of said diaphragm and said perforate portion of said disk.

2. The device of claim 1 wherein said diaphragm is provided with an integral peripheral ring, said ring retaining said disk and extending beyond the plane of said retained disk.

3. A spray gun of the class described which comprises:

a tubular body portion provided with a main passage,

the main passage extending from a water inlet portion to an outlet end portion;

a flat substantially rigid disk mounted in said inlet end portion and disposed across said inlet portion, said disk having a central imperforate area, an immediately adjacent annular perforate area, and an adjoiningouter imper-forate area;

a resilient diaphragm disposed across said disk, and

on the downstream side thereof, said resilient diaphragm having (1) a central slit portion, normally sealed when the water pressure is zero and openable in response to water pressure, (2) an intermediate annular portion adjoining said central slit portion, and (3) an outer annular imperforate portion, thicker than said intermediate annular portion and slit portion, aligned with and sealing said annular perforate area and said outer imperforate area of said disk when said water pressure is substantially zero;

a cylindrical shoulder mounted, on the inlet side of said gun and spaced downstream from said diaphragm when said diaphragm is undistended, and making sealing contact with said outer annular imperforate portion of said diaphragm when said diaphragm is distended in response to water pressure;

and valve means for communication of said main passage with a secondary passage.

4. In a spray gun of the type having a tubular body portion provided with a main passage extending from an inlet to an outlet end and having at the inlet end integralconnector means to a water inlet, and having integral connector means at one side thereof for a reservoir for chemical solution, the improvement which comprises:

a vent passage removed from said main passage and passing through said tubular body portion from said integral connector means for said reservoir to the atmosphere; and

a plug, having a head, a stem extending from said head and passing through said tubular body portion and said main passage, and means for selectively sealing said vent, said stem including a generally T-shaped passage having a normally horizontal port in the path of said main passage and provided with an abrupt enlargement in one portion thereof, and a normally vertical port passing from a bottom edge of said stem to said abrupt enlargement in said horizontal port, said stem further being rotatable within said body portion by rotation of said head such that said vent is sealed While said stem simultaneously blocks said main passage and said vent is exposed to the atmosphere while said horizontal port communicates with said main passage.

5. In a dev-ice for preventing backflow of a fluid, the

combination of:

a conduit for fluid having an inlet portion and an outlet portion;

a substantially rigid flat disk disposed across said conduit in said inlet portion and having a generally annular perforate portion surrounding a central imperforate portion; and

a generally flat resilient diaphragm disposed across said conduit on the outlet side of and adjacent said disk, said diaphragm having a flat central portion aligned with said central imperforate portion of said disk and having slits therein, and a plurality of generally annular sealing surfaces surrounding said central slits, said flat central portion and said annular sealing surfaces contacting said imperforate central portion of said disk when said diaphragm is in an undistended position to prevent backflow of fluid from said outlet pontion to said inlet portion through said slits in iaid diaphragm and said perforate portion of said dis 6. The combination of claim 5 wherein said plurality of sealing surfaces include an annular ring extending around said slits and an outer annular portion of said diaphragm surrounding said central portion.

References Cited by the Examiner UNITED STATES PATENTS RAPHAEL M. LUPO, Primary Examiner.

EVERETT w. KIRBY, Examiner. 

5. IN A DEVICE FOR PREVENTING BACKFLOW OF A FLUID, THE COMBINATION OF: A CONDUIT FOR FLUID HAVING AN INLET PORTION AND AN OUTLET PORTION; A SUBSTANTIALLY RIGID FLAT DISK DISPOSED ACROSS SAID CONDUIT IN SAID INLET PORTION AND HAVING A GENERALLY ANNULAR PERFORATE PORTION SURROUNDING A CENTRAL IMPERFORATE PORTION; AND A GENERALLY FLAT RESILIENT DIAPHRAGM DISPOSED ACROSS SAID CONDUIT ON THE OUTLET SIDE OF AND ADJACENT SAID DISK, SAID DIAPHRAGM HAVING A FLAT CENTRAL PORTION ALIGNED WITH SAID CENTRAL IMPERFORATE PORTION OF SAID DISK AND HAVING SLITS THEREIN, AND A PLURALITY OF GENERALLY ANNULAR SEALING SURFACES SURROUNDING SAID CENTRAL SLITS, SAID FLAT CENTRAL PORTION AND SAID ANNULAR SEALING SURFACES CONTACTING SAID IMPERFORATE CENTRAL PORTION OF SAID DISK WHEN SAID DIAPHRAGM IS IN AN UNDISTENDED POSITION TO PREVENT BACKFLOW OF FLUID FROM SAID OUTLET PORTION TO SAID INLET PORTION THROUGH SAID SLITS IN SAID DIAPHRAGM AND SAID PERFORATE PORTION OF SAID DISK. 